The Turkish government's priorities in fighting terrorism are coming under question, as it increasingly cracks down on proponents of Kurdish rights while, critics say, it fails to show the same zeal against the Islamic State.

On Tuesday, supporters of three jailed press freedom advocates gathered in Istanbul to protest the detentions. The three activists were detained Monday on terrorism charges for participating in a solidarity campaign in support of Ozgur Gundem, a pro-Kurdish newspaper.

The government defends the arrests, claiming those detained were producing propaganda on behalf of the PKK — the Kurdish rebel group which Turkish security forces are fighting. The jailing of the activists not only puts a spotlight on Turkey's sweeping anti-terror laws, but also raises questions on how those laws are being applied, says Atilla Yesilada, an Istanbul-based consultant with Global Source Partners.

"Anyone who says we should pursue peace with PKK or end this war are labeled as a [PKK] sympathizer,” Yesilada said. “And they are almost certain to go through some kind of court process. But most of the time, when the police brings the ISIS people to justice, either the prosecutor refuses to write an indictment or the courts let these people go on account that not enough evidence being found, which tells you where the priorities of Turkish state lie." ISIS is an acronym for Islamic State.

FILE - Militants from the Kurdistan Workers' Party, or PKK, run as they attack Turkish security forces in Nusaydin, Turkey, March 1, 2016.

Legal experts point out that the broad nature of the anti-terror laws means little evidence is needed to sustain a prosecution.

Release, escape

Doubts over the seriousness of Turkey's crackdown on Islamic State were heightened last month when five suspected Turkish members of Islamic State accused of large-scale arms smuggling escaped from an open prison in the country's Kocaeli province. Why high-profile jihadist suspects were held in a low-security facility has not been explained.

In March, an Istanbul court released the last seven of 94 suspects who had been held in pre-trial detention as part of the largest court case against Islamic State members in Turkey. Human rights groups say their release from pre-trial detention — even though they face serious charges of violence — contrasts with the thousands of pro-Kurdish activists who are being held in pre-trial detention on charges not linked to violence.

Kadri Gursel, a political columnist for Turkey's Cumhuriyet newspaper and Al-Monitor website, says the difference in the treatment of accused Islamic State members and pro-Kurdish activists can be explained by the fact that Ankara views Islamic State as a useful tool in fighting the PKK in neighboring Syria.

"Turkey prefers Daesh, ISIS, on the south of their Syria border instead of seeing Kurds. Simply, they prefer ISIS to [the] Kurds," Gursel said.

FILE - Rescue workers are seen at the scene of a traffic police station and lodging quarters attacked with a car bomb by Kurdish rebels, in Nusaybin, southeastern Turkey, March 4, 2016.

Turkish President Recep Tayyip Erdogan said last year that the PKK and its affiliate in Syria were more of a threat to Turkey than Islamic State. Last week, however, a senior Turkish official briefing foreign journalists on condition of anonymity angrily rejected charges of turning a blind eye to Islamic State activities, saying this was impossible given the group was responsible for so many deadly bombings in Turkey.

Also last week, a Turkish court sentenced three foreign members of Islamic State to life imprisonment for killing two members of Turkey's security forces.

Worrying trend

Despite such convictions, analyst Yesilada warns that Turkey could end up a paying a very high price for its Islamic State policy.

"You see, the ISIS network in Turkey is alive and very healthy, and you look at the Pakistani experience and how they harbored and nurtured the Taliban and what Taliban did to them. You do see that leads to disaster," Yesilada said.

Western intelligence officials have also drawn a comparison between Turkey and Pakistan. They point to a worrying new trend of Turkish security forces expelling suspected Islamic State militants to countries like Iraq and Sudan, rather than prosecuting them and getting information from them.

Turkey's government, however, says it has prevented tens of thousands of would-be jihadists from entering the country and insists it remains a key ally in the war against Islamic State.